1) Astray 2) Being off target 3) Blowing it 4) Blundering 5) Capable of making an error 6) Committing mistakes 7) Dropping the ball 8) Error-prone 9) Fallible 10) Flubbing it 11) Fumbling 12) Getting it wrong 13) Going astray 14) Going awry 15) Going wrong 16) Goofing 17) In error 18) Like a sinner Found on https://www.crosswordclues.com/clue/erring